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    <center>Scilab Function</center>
    <div align="right">Last update : 25/05/2004</div>
    <p>
      <b>svplot</b> -  singular-value sigma-plot</p>
    <h3>
      <font color="blue">Calling Sequence</font>
    </h3>
    <dl>
      <dd>
        <tt>[SVM]=svplot(sl,[w])  </tt>
      </dd>
    </dl>
    <h3>
      <font color="blue">Parameters</font>
    </h3>
    <ul>
      <li>
        <tt>
          <b>sl</b>
        </tt>: <tt>
          <b>syslin</b>
        </tt> list (continuous, discrete or sampled system)</li>
      <li>
        <tt>
          <b>w</b>
        </tt>: real vector (optional parameter)</li>
    </ul>
    <h3>
      <font color="blue">Description</font>
    </h3>
    <p>
    computes for the system <tt>
        <b>sl=(A,B,C,D)</b>
      </tt>
    the singular values of its transfer function matrix:</p>
    <pre>

             G(jw) = C(jw*I-A)B^-1+D
or
             G(exp(jw)) = C(exp(jw)*I-A)B^-1+D
or
             G(exp(jwT)) = C(exp(jw*T)*I-A)B^-1+D
   
    </pre>
    <p>
    evaluated over the frequency range specified by <tt>
        <b>w</b>
      </tt>. (T is the sampling
    period, <tt>
        <b>T=sl('dt')</b>
      </tt> for sampled systems).</p>
    <p>
      <tt>
        <b>sl</b>
      </tt> is a <tt>
        <b>syslin</b>
      </tt> list representing the system
    <tt>
        <b>[A,B,C,D]</b>
      </tt> in state-space form. <tt>
        <b>sl</b>
      </tt> can be continous or
    discrete time or sampled system.</p>
    <p>
    The <tt>
        <b>i</b>
      </tt>-th column of the output matrix <tt>
        <b>SVM</b>
      </tt> contains the singular
    values of <tt>
        <b>G</b>
      </tt> for the <tt>
        <b>i</b>
      </tt>-th frequency value <tt>
        <b>w(i)</b>
      </tt>.</p>
    <pre>

SVM = svplot(sl)
   
    </pre>
    <p>
    is equivalent to</p>
    <pre>

SVM = svplot(sl,logspace(-3,3))  (continuous)
   
    </pre>
    <pre>

SVM = svplot(sl,logspace(-3,%pi)) (discrete)
   
    </pre>
    <h3>
      <font color="blue">Examples</font>
    </h3>
    <pre>

x=logspace(-3,3);
y=svplot(ssrand(2,2,4),x);
xbasc();plot2d1("oln",x',20*log(y')/log(10));
xgrid(12)
xtitle("Singular values plot","(Rd/sec)", "Db");
 
  </pre>
    <h3>
      <font color="blue">Author</font>
    </h3>
    <p>F.D; ;   </p>
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